“Dry” Eye

“Dry” eye is the commonest cause of irritated, burning, watery, itchy eyes with morning mucus accumulation. Dry is not a great description, because most dry eye patients make enough watery tears, but not enough oil to keep the tears from quickly evaporating. Commonly, the symptoms are incorrectly attributed to allergies, infection or foreign body, but antihistamine and antibiotic drops will only aggravate the situation before the correct diagnosis is made.

Unfortunately, lubricating drops are useless for most patients, though they may give a few minutes of relief, like licking chapped lips. (Lubricating drops with preservatives are even worse than preservative-free lubricating drops and should not be used.) Restasis and Xiidra are approved for dry eye treatment in the US, but European authorities did not approve those drugs because they were deemed minimally effective — an assessment I agree with. Miebo is a PFAS (per/poly-fluoro alkyl substance) chemical which puts a slippery coating on the cornea and probably gives better relief than other preservative-free lubricating drops. Unfortunately, PFAS are “forever chemicals” which last for about 1000 years and generally cause a wide range of health problems to humans and other creatures. Examples of PFAS include Teflon, non-stick cookware coatings, waterproof coatings on clothing, fire-fighting foams. Miebo is sold over the counter in Europe for about $20; in the US it costs about $200 if not covered by insurance.

The front surface of the eye (cornea and conjunctiva) are lubricated by both water and oil: salt water from the lacrimal gland and oil from the Meibomian glands (thin tubes, about 50 in each eye lid). Usually the oil glands are more deficient than the lacrimal glands, though both may be impaired. It is difficult to effectively improve lacrimal gland flow, but oil flow can be improved by heating up the eye lids so that clogged oils melt and oil gland flow improves.

HOT COMPRESSES The lids can be heated by a hot (not warm) wet towel or microwaveable pack (like Bruder or Core Products); standing longer in the shower won’t work. Several minutes, 2-4 times a week, every week of the year is sufficient for most patients; but some benefit from daily hot compresses. Dry eye patients older than 60 should expect that the problem will always recur if hot compresses are stopped. Hot compresses should be thought of as a life-long maintenance. Stopping for weeks will worsen the problem substantially.

SERUM TEARS Lubricating drops made from your own blood work very well. An outside service draws your blood, processes it to discard the red blood cells, and ships you bottles with your own plasma (blood serum). A single blood draw will give a 6 months supply and costs about $500 (which is not covered by insurance. This option is for people with significant symptoms despite doing hot compresses consistently for several months.

CHALAZION Chalazions (red lump on the lid lasting a few weeks or months) are more common in dry eye patients because the lump is a consequence of poor oil flow. If the oil flow through an oil gland becomes completely obstructed, there will be a swollen red lump on the lid. If the gland bursts, the oil will be trapped in the skin, and it will take weeks or months for white blood cells to remove it. Sometimes pressure inside the skin causes the oil-filled white blood cells to drain through the skin or inner lid. Since chalazion is not an infection, antibiotic drops and pills are useless. Dry eye patients with impaired oil gland flow commonly get chalazia because the slow oil flow sometimes stops completely.